Laboratory for Atmospheres 2003 Technical Highlights: Section 4 Major Actvities

The previous section provided a snapshot of the activities pursued in the Laboratory for Atmospheres. This section presents a more complete picture of our work in measurements, field campaigns, data sets, data analysis, and modeling. In addition, we summarize the Laboratory's support for the National Oceanic and Atmospheric Administration's (NOAA) remote sensing requirements. The section concludes with a listing of project scientists, a description of interactions with other scientific groups, and a statement of our interest in commercialization and technology transfer.

4.1 Measurements

Studies of the atmospheres of Earth and the planets require a comprehensive set of observations, relying on instruments borne on spacecraft, aircraft, balloons, or those that are ground-based. Our instrument systems 1) provide information leading to basic understanding of atmospheric processes, and 2) serve as calibration references for satellite instrument validation.

Many of the Laboratory's activities involve developing concepts and designs for instrument systems for spaceflight missions, and for balloon-, aircraft-, and ground-based observations. Airborne instruments provide critical in situ and remote measurements of atmospheric trace gases, aerosol, ozone, and cloud properties. Airborne instruments also serve as stepping-stones in the development of spaceborne instruments, and serve an important role in validating spacecraft instruments.

Table 3 shows the principal instruments that were built in the Laboratory or for which a Laboratory scientist has had responsibility as Instrument Scientist. The instruments are grouped according to the scientific discipline each supports. Table 3 also indicates each instrument's deployment—in space, on aircraft, balloons, on the ground, or in the laboratory. Instrument details are not presented here, but appear in a separate publication, the “Instrument Systems Report.”

Table 3: Principal instruments supporting scientific disciplines in the Laboratory for Atmospheres.

 

Atmospheric Structure and Dynamics

Atmospheric Chemistry

Clouds and Radiation

Planetary Atmospheres/Solar Influences

Space

 

Total Ozone Mapping Spectrometer (TOMS) - Earth Probe (EP)

Earth Polychromatic Imaging Camera (EPIC) - DSCOVR

 

Gas Chromatograph Mass Spectrometer (GCMS)

Cassini Huygens Probe

Ion and Neutral Mass Spectrometer (INMS) Cassini Orbiter

Aircraft

ER-2 Doppler Radar (EDOP)

Holographic Airborne

Rotating Lidar Instrument Experiment (HARLIE)

Airborne Raman Ozone, Temperature, and Aerosol Lidar (AROTAL)

Raman Airborne Spectroscopic Lidar (RASL)

Cloud Physics Lidar (CPL)

cloud THickness from Offbeam Returns (THOR) Lidar

Leonardo Airborne Simulator (LAS)

Cloud Radar System (CRS)

 

Ground/

Laboratory/

Development

Scanning Raman Lidar (SRL)

Goddard Lidar Observatory for Winds (GLOW)

Lightweight Rain Radiometer

(LRR-X)

Stratospheric Ozone Lidar Trailer Experiment

(STROZ LITE)

Compact Hyperspectral Mapper for Environmental Remote Sensing Applications

(CHyMERA)

Aerosol and Temperature Lidar (AT Lidar)

Brewer UV Spectrometer

Goetz Radiometer

Aerosol Lidar (AL)

L2-SVIP (IIP)

Geo Spec (IIP)

Micro Pulse Lidar (MPL)

COmpact Vis IR (COVIR)

Surface Measurements for Atmospheric Radiative Transfer (SMART)-Chemical, Optical & Microphysical Measurements of In-situ Troposphere (COMMIT)

 

4.2 Field Campaigns

Field campaigns typically use the resources of NASA, other agencies, and other countries to carry out scientific experiments, to validate satellite instruments, or to conduct environmental impact assessments from bases throughout the world. Research aircraft, such as the NASA ER-2 and DC-8, serve as platforms from which remote sensing and in situ observations are made. Ground systems are also used for soundings, remote sensing, and other radiometric measurements. In 2003, Laboratory personnel supported many such activities as scientific investigators, or as mission participants, in the planning and coordination phases.

Aerosol-IOP

The Goddard Surface-sensing Measurements for Atmospheric Radiative Transfer (SMART) facility deployed successfully in the Aerosol-Intensive Observational Period (IOP), conducted at the Department of Energy's Atmospheric Radiation Measurement (ARM) Program Southern Great Plains (SGP) site in north central Oklahoma for the entire month of May 2003. This experiment used ground and airborne measurements of aerosol absorption, scattering, and extinction over the ARM SGP site to characterize the routine ARM aerosol measurements, and to help resolve differences between measurements and models of diffuse irradiance at the surface. SMART is a mobile, ground-based remote sensing facility (8'x8'x20' weather-sealed trailer with thermostatic temperature control), including a sun photometer, a rotating shadow-band radiometer, a micro-pulse lidar, a solar spectrometer, an interferometer, a whole-sky imager, a microwave radiometer, an array of shortwave and longwave flux radiometers, four trace gas concentration analyzers (i.e., CO, SO2, NOx, and O3), and a system of surface meteorological probes.

During the IOP, a variety of closure experiments on aerosol optical properties and their radiative influence were carried out over the SGP site and SMART. The major objective of SMART in the ARM/Aerosol IOP was to study aerosol optical properties (scattering, absorption, and extinction) using a number of different instruments simultaneously with measurements of direct and diffuse solar radiation. Elevated aerosol layers were frequently observed by SMART micro-pulse lidar. These layers, 2 - 5 km aloft, are often the result of long-range transport of smoke, dust, or pollution, which may cast substantial impact on the atmospheric radiation budget. For further information, contact Si-Chee Tsay (Si-Chee.Tsay-1@nasa.gov).

Advanced Microwave Scanning Radiometer - EOS (AMSR-E)

The Thickness from Offbeam Returns (THOR) instrument was deployed in the Antarctic AMSR-E Sea Ice (AASI) field campaign from August 19 - September 16, 2003. The primary purpose of the field campaign was to study Antarctic ice cover. A NASA P3 from Wallops Flight Facility, Virginia was used as the platform for the aircraft instruments. Chief scientist, Josefino C. Comiso of Code 971, was responsible for the seven instruments on board the P3. Chilean Air Force facilities in Punta Arenas, Chile served as the mission staging area. The main areas of study were located around the Antarctic's Palmer Peninsula in the Weddell and Bellinghaussen seas. The THOR instrument, a laser-based system, was used to measure sea ice thickness. A mechanical problem with the aircraft forced cancellation of most flights, and as a result a second AASI experiment is planned for August - September 2004. For further information contact Robert Cahalan (Robert.F.Cahalan@nasa.gov).

Atmospheric Infrared Sounder (AIRS) Water Vapor Experiment - Ground (AWEX-G)

The Code 912 Scanning Raman Lidar participated in AWEX-G, October 27 - November 19, 2003, (http://www.db.arm.gov/). The NASA-sponsored Aqua validation activity included the use of different water vapor profiling radiosonde and Raman lidar systems for acquisition of measurements during Aqua overpasses. The comparison of these measurements with AIRS on board Aqua, through the use of the AIRS forward model, has revealed apparent calibration differences among the various water vapor profiling technologies being used. The differences are largest in the upper troposphere (UT) where, even after excluding the results from two of the instruments that showed the largest disagreements, differences of 15% in relative humidity (RH) remained. This has created questions both about the sensor technologies themselves, and more importantly, from the validation perspective, of what source of water vapor information to use for AIRS validation particularly in the UT.

To address these questions, a suite of water vapor profiling sensors in use in the Aqua validation activity was deployed to the Department of Energy's (DOE) SGP ARM site in northern Oklahoma. The instruments included the Code 912 Scanning Raman Lidar (SRL) and various radiosonde types including Vaisala RS-80, RS-90, RS-92, Internet, Sippican, SnowWhite, and a proprietary frostpoint sensor developed by NOAA and the University of Colorado. In addition, permanently stationed ARM water vapor sensors were in use during the experiment including the ARM Raman Lidar, the microwave radiometer and the Atmospheric Emitted Radiance Interferometer (AERI).

During the more than three weeks of AWEX-G, more than 100 radiosonde packages were flown under a range of meteorological conditions. The SRL was operated for more than 50 hours in conjunction with these special sonde flights. This comprehensive data set will be used to study systematic and random errors that exist among these water vapor profilers. These errors will be characterized with the goal of determining the most accurate way of processing water vapor profile data from radiosondes and Raman lidar for use in AIRS validation. For more information contact David Whiteman (David.N.Whiteman@nasa.gov).

CPL Activities

During 2003, the ER-2 Cloud Physics Lidar (CPL) participated in three major field campaigns. During these missions, the CPL was used primarily for satellite validation (MODIS, GLAS, AIRS) and also to provide data to be used in studies to improve weather prediction models.

During 2003, the ER-2 Cloud Physics Lidar (CPL) participated in three major field campaigns. During these missions, the CPL was used primarily for satellite validation (i.e., the Moderate Resolution Imaging Spectroradiometer [MODIS], Geoscience Laser Altimeter System [GLAS], and AIRS), and also to provide data to be used in studies to improve weather prediction models.

From February 18 - March 13, 2003, the CPL was part of the Observing System Research and PRedictability Experiment (THORPEX) Pacific field campaign (http://www-angler.larc.nasa.gov/thorpex). Flown out of Honolulu, Hawaii, the 10 flights of this mission were designed to address four primary issues:

1)    Improve numerical weather forecasts, which is a goal of the NOAA Winter Storms Research Program;

2)    Validation of NASA EOS satellite data products, including Terra; Aqua; and the Ice, Cloud, and Land Elevation Satellite (ICESat)—during this mission the first three underflights of the GLAS instrument on ICESat were also accomplished;

3)    Validation of the Integrated Program Office (IPO) NPOESS Atmospheric Sounder Testbed (NAST) satellite instrument; and

4)    Improve aviation weather products as part of a joint NASA - Federal Aviation Administration (FAA) program.

From October 13 - November 1, 2003, the CPL was based out of NASA Dryden Flight Research Center for GLAS validation flights. Seven successful underflights of ICESat were conducted. Data from these underflights will be used to calibrate the GLAS lidar instrument, particularly the 532 nm atmospheric channel.

From November 17 - December 18, 2003, the CPL participated in the second of a series of THORPEX field missions. The THORPEX - Atlantic field campaign (http://angler.larc.nasa.gov/bangor) was based out of Bangor, Maine. Eleven flights were conducted with a primary focus of improving forecasts of winter storms and supporting research related to aviation safety.

For more information on the CPL instrument, or for access to CPL data, visit http://cpl.gsfc.nasa.gov, or contact Matthew McGill (matthew.j.mcgill@nasa.gov).

HARLIE at the Pennsylvania Mobile Radar Experiment (PAMREX)

HARLIE deployment at PAMREX, State College, Pennsylvania, was held on November 24, 2003. Geary Schwemmer and David Miller (912) deployed the HARLIE instrument to participate in PAMREX that took place near the Pennsylvania State University (PSU) campus in State College. HARLIE is a unique conical scanning aerosol and cloud lidar instrument, which uses a Goddard developed holographic telescope. The objectives of PAMREX were to study the interaction of fronts and thunderstorms with local ridges and valleys, terrain-induced atmospheric circulations, and phenomena owing to atmospheric interactions with Lake Erie. Graduate students in the Department of Electrical Engineering were trained to operate HARLIE for the duration of PAMREX. A real-time, Web-based display that also allowed for remote control of the system was set up by the students. The data was available to the students for individual research projects. Complementary measurements of cloud base were recorded using a commercial ceilometer. These measurements will be used to validate the algorithm developed by David Miller to derive cloud coverage from HARLIE backscatter data. Additional information on the colloquium and PAMREX can be found at:

http://www.met.psu.edu/. Information on HARLIE can be found at http://harlie.gsfc.nasa.gov/, or by contacting (Geary.K.Schwemmer@nasa.gov).

SAGE III Ozone Loss and Validation Experiment (SOLVE II) Campaign

SOLVE II was a measurement campaign designed to 1) examine the processes controlling ozone levels at mid- to high latitudes, and 2) acquire correlative data needed for the validation of the Stratospheric Aerosol and Gas Experiment (SAGE) III satellite measurements. SAGE-III is a NASA instrument on board a Russian Meteor-3 satellite platform. SAGE-III is primarily used to quantitatively assess high-latitude ozone loss.

The SOLVE II mission was conducted during January 2003. Measurements were made in the Arctic high-latitude region during winter using the NASA DC-8 aircraft, as well as two heavy lift balloon flights, a number of smaller balloon packages, and ground-based instruments. The NASA DC-8 arrived in Kiruna, Sweden, slightly north of the Arctic Circle on January 9, 2003. A total of 11 science flights were conducted out of Kiruna, and the DC-8 returned to NASA Dryden on February 6, 2003.

Ozone loss in the polar stratosphere is directly caused by catalytic chlorine and bromine reactions. The high levels of reactive chlorine occur because of reactions of reservoir chlorine species on the surfaces of polar stratospheric clouds (PSCs). PSCs were observed by the NASA DC-8 lidar systems on the flight of January 9, 12, 14, and February 4, 2003 at altitudes from 65,000 - 80,000 feet. In Figure 4-1, we see a PSC cloud that was observed over southern Sweden on January 14, 2003. Three types of PSCs are common in the Polar Region: type Ia (small crystals), type Ib (small liquid droplets), and type II (large crystals). The type Ia PSCs are probably nitric acid hydrates; the type Ib are probably solutions of nitric acid, water, and sulfuric acid; while the type II PSCs are water ice crystals. The PSC in Figure 4-1 is probably a water ice cloud because of the strong coloration from the ice crystal refraction.

Picture of PSC taken from the NASA DC-8 over southern Sweden on January 14, 2003. Photo by Paul A. Newman.

Figure 4-1. Picture of PSC taken from the NASA DC-8 over southern Sweden on January 14, 2003. Photo by Paul A. Newman.

As mentioned earlier, two chlorine compounds (HCl and ClONO2) that normally do not destroy ozone can collect on the surfaces of PSC particles. On these surfaces, chemical reactions convert the HCl and ClONO2, to Cl2 and HNO3. With a small amount of sunlight, the Cl2 is broken down and begins to catalytically destroy ozone. During the winter of 2002 - 2003, the polar vortex was cold and had moved southward toward Europe, exposing the air to sunlight. Normally, ozone values in the core of the vortex near 20 km would be approximately 3 ppm, however, because of the high levels of reactive chlorine, ozone steadily decreased over the course of the month.

ozone values observed on the flight from Kiruna, Sweden to California on February 6, 2003

Figure 4-2. Ozone values observed on the flight from Kiruna, Sweden to California on February 6, 2003. The x-axis of the figure shows the time, while the y-axis shows altitude. The polar vortex was situated over Kiruna, such that ozone values at 20 km on the left of the figure are inside the polar vortex. Typically, values of ozone inside the vortex in January would be near values of 3000 ppbv (the aqua color); however, during early February, these values are near 1500 ppbv, suggesting very large ozone losses inside the polar vortex.

These initial results are only qualitative, and will require further processing and quantitative analysis. These SOLVE II results will be directly used to quantify ozone loss in the vortex. The ozone values and ozone loss will then be compared to the SAGE III ozone values to validate our global observations of ozone. For more information on SOLVE II, contact Paul Newman at Paul.A.Newman@nasa.gov, or visit the SOLVE II Web site: http://cloud1.arc.nasa.gov/solveII/index.html

4.3 Data Sets

In the previous discussion, we examined the array of instruments and some of the field campaigns that produce the atmospheric data used in our research. The raw and processed data from these instruments and campaigns is used directly in scientific studies. Some of this data, plus data from additional sources, is arranged into data sets useful for studying various atmospheric phenomena. The major data sets are described in the following paragraphs.

50-Year Chemical Transport Model (CTM) Output

A 50-year simulation of stratospheric constituent evolution has been completed using the Code 916 three-dimensional chemistry and transport model. Boundary conditions were specified for chlorofluorocarbons, methane, and N2O appropriate for the period 1973 - 2023. Sulfate aerosols were also specified, and represent the eruptions of El Chichon and Mt. Pinatubo. The model output is available on the Code 916 science system; software to read the output is also available. Although the CTM itself is run at 2° x 2.5° latitude/longitude horizontal resolution; the output is stored at 4° x 5° latitude/longitude. Higher resolution files are available from UniTree, the Code 930 archive. The model output stored on the science system is for 6 days each month (1, 5, 10, 15, 20, 25); daily fields are saved on UniTree. Some details about this and other CTM simulations are available from the Code 916 Web site at http://code916.gsfc.nasa.gov/Public/Modelling/3D/exp.html. Questions or comments should be addressed to Anne Douglass (Anne.R.Douglass@nasa.gov).

Global Precipitation

An up-to-date, long, continuous record of global precipitation is vital to a wide variety of scientific activities. These include initializing and validating numerical weather prediction and climate models, providing input for hydrological and water cycle studies, supporting agricultural productivity studies, and diagnosing intra- and interannual climatic fluctuations on regional and global scales.

At the international level, the Global Energy and Water Cycle Experiment (GEWEX) component of the World Climate Research Programme (WCRP) established the Global Precipitation Climatology Project (GPCP) to develop such global data sets. Scientists working in the Laboratory have led the GPCP effort to merge microwave data from low-Earth - orbit satellites, infrared data from geostationary satellites, and data from ground-based rain gauges to produce the best estimates of global precipitation.

Version 2 of the GPCP merged data set provides global, monthly precipitation estimates for the period, January 1979 to the present. Updates are being produced on a quarterly basis. The release includes input fields, combination products, and error estimates for the rainfall estimates. The data set is archived at World Data Center A (located at the National Climatic Data Center in Asheville, North Carolina) and at the Goddard Distributed Active Archive Center (DAAC). Evaluation is ongoing for this long-term data set in the context of climatology, El Niño Southern Oscillation (ENSO)-related variations and trends, and comparison with the new TRMM observations.

Development of data sets with finer time resolution (daily and 3 hr) is proceeding. A daily, global analysis for the period 1997 - present has also been completed for the GPCP and is available from the archives. A quasi-global, 3 hr resolution rainfall analysis combining TRMM and other satellite data is being produced in real-time, with images and data available through the TRMM Web site. A research version of this 3 hr data set will soon be available (mid-2004) for the TRMM observation period from January 1, 1998, to the present. For more information, contact Robert Adler (Robert.F.Adler@nasa.gov).

MPLNET data sets

The Micro-Pulse Lidar Network (MPLNET) is composed of ground-based lidar systems, co-located with sun - sky photometer sites in the NASA Aerosol Robotic Network (AERONET). The MPLNET project uses the MPL system, which is a compact and eye-safe lidar capable of determining the range of aerosols and clouds continuously in an autonomous fashion. The unique capability of this lidar to operate unattended in remote areas makes it an ideal instrument to use for a network. The primary purpose of MPLNET is to acquire long-term observations of aerosol and cloud vertical structure at key sites around the world. These types of observations are required for several NASA satellite validation programs, and are also a high priority in the Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). The combined lidar and sun photometer measurements are able to produce quantitative aerosol and cloud products, such as optical depth, sky radiance, vertical structure, and extinction profiles. MPLNET results have contributed to studies of dust, biomass, marine, and continental aerosol properties, the effects of soot on cloud formation, aerosol transport processes, and polar clouds and snow. MPLNET data has also been used to validate results from NASA satellite sensors, such as the Multi-Angle Imaging Spectroradiometer (MISR) and TOMS, and to help construct algorithms used to interpret space-based lidar data from GLAS. Further information on the MPLNET project, and access to data, is available online at http://mplnet.gsfc.nasa.gov. For questions on the MPLNET project contact Judd Welton (Judd.Welton@nasa.gov).

Multiyear Global Surface Wind Velocity Data Set

The Special Sensor Microwave Imagers (SSM/I) aboard Defense Meteorological Satellite Program (DMSP) satellites have provided a large data set of surface wind speeds over the global oceans from July 1987 to the present. These data are characterized by high resolution, coverage, and accuracy, but their application was limited by the lack of directional information. In an effort to extend the applicability of these data, our scientists developed methodology to assign directions to the SSM/I wind speeds and to produce analyses using these data. This methodology has been used since 1987 to generate global SSM/I wind vectors. These data are currently being used in a variety of atmospheric and oceanic applications and are available to interested investigators. In addition, a new higher resolution integrated data set in which data from all SSM/I and available scatterometers from 1987 to the present is now being produced. For more information, contact Robert Atlas (Robert.M.Atlas@nasa.gov).

SHADOZ (Southern Hemisphere ADditional OZonesondes) Data Set

Initiated by NASA's Goddard Space Flight Center in 1998, in collaboration with NOAA and meteorological and space agencies from around the world, SHADOZ augments balloonborne ozonesonde launches in the tropics and subtropics. SHADOZ presently includes 12 sites, including one 3°N of the equator, i.e., in the Northern Hemisphere (Suriname). Launches are usually weekly at each station. SHADOZ archives ozone and temperature profile data at a user-friendly, open Web site: http://croc.gsfc.nasa.gov/shadoz. SHADOZ ozone data are used for a number of purposes:

SHADOZ has led to significant scientific advances. For example, satellite retrievals are using longitudinal and seasonal variations in tropical ozone for the first time. In addition, by having so many profiles, it has been possible to improve accuracy and precision of the ozonesonde measurement under tropical conditions. All SHADOZ stations fly a radiosonde- electrochemical concentration cell (ECC) ozonesonde combination. The World Meteorological Organization (WMO) uses SHADOZ as the paradigm for developing new ozone sounding stations in WMO's Global Atmospheric Watch (GAW) program. For additional details, contact Anne Thompson (Anne.M.Thompson@nasa.gov). The archive URL is located at : http://croc.gsfc.nasa.gov/shadoz

Skyrad Ground Based Observations

A new measurement program, called Skyrad, has been initiated in the Laboratory to investigate radiative transfer properties of the atmosphere in the near ultraviolet (300 - 400 nm). The purpose of these observations is to test the accuracy of the Laboratory's highly regarded radiative transfer models, to improve ozone algorithms (both ground and space), and to calibrate orbiting ozone satellite radiance data. These observations are taken from the Laboratory's Radiometric Development and Calibration Facility which houses several ground-based instruments, notably the Shuttle Solar Backscatter Ultraviolet (SSBUV), which flew on the Shuttle eight times from 1989 - 1996. SSBUV, which has been used as the prelaunch calibration transfer standard for all ozone instruments using the BUV technique, was reconfigured to take zenith sky observations from the laboratory while remaining in a controlled environment to maintain a high degree of calibration. This location is ideally suited for these studies because AERONET aerosol and Brewer ozone instruments are nearby.

Nearly two years of zenith sky data have been taken over a range of sky conditions. In addition, an accurate set of tables of expected zenith sky radiances were calculated for conditions over Goddard including a range of aerosol characteristics and ozone amounts. Comparisons of observations and models resulted in differences of less than 3%. The zenith data are also being used to derive ozone column amounts and aerosol characteristics in the ultraviolet. The column ozone algorithm will be very useful for ground-based measurements at high solar zenith angles where conventional systems have greater errors. These data are also being used to track the long-term degradation of TOMS by comparing TOMS nadir radiances with SSBUV zenith sky radiances. Initial results show this is feasible. We also plan to use this method to track the calibration of existing and upcoming ozone instruments flown by Europe, NASA, and NOAA. Small day-to-day variations are observed in the zenith sky data, which cannot be explained by ozone- or the conventional aerosol observations. It is proposed that these variations may be due to yet unknown aerosol properties that are absorbing in the ultraviolet. This may have implications on the variability of harmful ultraviolet surface irradiance amounts and the amount of radiation available for pollution photolysis. For more information, contact Ernest Hilsenrath (Ernest.Hilsenrath@nasa.gov.)

TIROS Operational Vertical Sounder Pathfinder

The Pathfinder Projects are joint NOAA - NASA efforts to produce multiyear climate data sets using measurements from instruments on operational satellites. One such satellite-based instrument suite is TOVS. TOVS is composed of three atmospheric sounding instruments: the High Resolution Infrared Sounder-2 (HIRS-2), the Microwave Sounding Unit (MSU), and the Spectral Sensor Unit (SSU). These instruments have flown on the NOAA Operational Polar Orbiting Satellite since 1979. We have reprocessed TOVS data from 1979 to the present, using an algorithm developed in the Laboratory to infer temperature and other surface and atmospheric parameters from TOVS observations.

The TOVS Pathfinder Path A data set covers the period 1979 - 2003 and consists of global fields of surface skin and atmospheric temperatures, atmospheric water vapor, cloud amount and cloud height, Outgoing Longwave Radiation (OLR) and clear sky OLR, and precipitation estimates. The data set includes data from TIROS N, NOAA 6, 7, 8, 9, 10, 11, 12, and 14. Equivalent future data sets will be produced from NOAA 16 and 17 Advanced TOVS (ATOVS) data and from AIRS data on EOS Aqua. We have demonstrated that TOVS data can be used to study interannual variability of surface and atmospheric temperatures and humidity, cloudiness, OLR, and precipitation. We have developed the 25-year TOVS Pathfinder Path A data set. The TOVS precipitation data is being incorporated in the monthly and daily GPCP precipitation data sets. We are developing improved methodologies to analyze ATOVS data to produce a future climate data set.

We have also developed the methodology used by the AIRS science team to generate products from AIRS for weather and climate studies, and continue to improve the AIRS science team retrieval algorithm. The Goddard DAAC has been producing AIRS level-2 soundings since August 2002 using an early version of the AIRS science team retrieval algorithm. In joint work with Robert Atlas, AIRS temperature profiles derived using an improved retrieval algorithm have been assimilated into the Laboratory forecast analysis system and have shown a significant improvement in weather prediction skill. For more information, contact Joel Susskind (Joel.Susskind-1@nasa.gov).

TOMS Data Sets

Since the Atmospheric Chemistry and Dynamics Branch first formed, it has been tasked with making periodic ozone assessments. Through the years the branch has led the science community in conducting ozone research by making measurements, analyzing data, and modeling the chemistry and transport of trace gases that control the behavior of ozone. This work has resulted in a number of ozone and related data sets based on the TOMS instrument. These data sets are described on the Atmospheric Chemistry and Dynamics Branch Web site, which is linked to the Laboratory Web site, http://atmospheres.gsfc.nasa.gov/. Click on the Code 916 branch site, and then click on Data Services. The TOMS spacecraft and data sets are then found by clicking on TOMS Total Ozone data, or directly on http://toms.gsfc.nasa.gov/ozone/ozone.html.

Merged TOMS Data Set

We have recently updated our merged satellite total ozone data set. We have transferred the calibration from the original six satellite instruments to the NOAA 16 SBUV/2. This allows us to extend the record despite issues with the calibration of the Earth Probe TOMS (EP-TOMS) for the last few years. The data sets now extend through the end of 2003. The data, and information about how they were constructed, can be found at http://code916.gsfc.nasa.gov/Data_services/merged. It is expected that these data will be useful for trend analyses for ozone assessments and for scientific studies in general. For further information, contact Richard Stolarski (Richard.S.Stolarski@nasa.gov) or Stacey Frith (smh@code916.gsfc.nasa.gov).

Aerosol Products from TOMS

Laboratory scientists are generating a unique new data set of atmospheric aerosol by reanalyzing the 17-year data record of Earth's ultraviolet albedo as measured by TOMS. Since 1996, Laboratory staff members have developed techniques for extracting aerosol information from measured UV radiances. TOMS aerosol detection capability is based on the change in spectral contrast of upwelling near UV radiances at the top of an aerosol laden atmosphere. The spectral contrast variability is measured in relation to that of a pure molecular atmosphere. The near UV technique differs from conventional visible methods of aerosol detection in that the UV measurements can separate UV absorbing aerosol (such as desert dust, smoke from biomass burning, and volcanic ash) from nonabsorbing aerosol (such as sulfates, sea salt, and ground-level fog). In addition, the UV technique can detect aerosol over water and land surfaces, including deserts where traditional visible and near-IR methods do not work. TOMS aerosol data are currently available in the form of a contrast index and as near-ultraviolet extinction optical depth.

The aerosol index is a qualitative parameter that provides excellent information about absorbing aerosol sources, transport, and seasonal variation of a variety of aerosol types (Figure 4-3). The aerosol index is the only known remote-sensing technique capable of detecting desert dust, smoke, and volcanic ash aerosol over snow or ice and clouds. The most recent version of the data, based on Version 8 reprocessing, has been released.

The TOMS Aerosol Display Image is a 3 day composite image of the data recorded by the spacecraft.

Figure 4-3. The TOMS Aerosol Display Image is a 3-day composite image of the data recorded by the spacecraft. Horace Mitchell of the Goddard Scientific Visualization Studio (SVS) is responsible for developing the Display Imaging Software for the TOMS Aerosol Product, http://svs.gsfc.nasa.gov/. Jay Herman is the EP-TOMS Principal Investigator (PI).

The science value of the TOMS aerosol information has been enhanced by the application of an inversion procedure to the TOMS measured radiances to derive the near-ultraviolet extinction optical depth and single-scattering albedo of aerosol. The TOMS aerosol algorithm has been applied to the entire TOMS record to produce the longest available data set on aerosol optical depth over the oceans and the continents at a 1° x 1° resolution. The TOMS aerosol optical depth (Figure 4-4) record (available at http://toms.gsfc.nasa.gov/aerosols/aot.html) is a useful data set for the analysis of aerosol trends, especially over land areas, where aerosol sources are located, and no other long-term records are available. For more information on the TOMS aerosol optical depth and single-scattering albedo products, contact Omar Torres (torres@tparty.gsfc.nasa.gov).

Zonally averaged TOMS aerosol optical depth as a function of time.

Figure 4-4. Zonally averaged TOMS aerosol optical depth as a function of time.

An example of a daily TOMS ozone data set is illustrated in Figure 4-5.

EP/TOMS polar image and partial day dataset updated for March 8, 2004.

Figure 4-5. Polar image and partial day data set updated for March 8, 2004. The latest daily image and a full-day data set are updated once each day (when we have a full day of data). This near-real time system is automated.

Erythermal UV and UV irradiance products

Example of TOMS global image of daily erythemal UV exposure.

Figure 4-6 is an example of TOMS global image of daily erythemal UV exposure.


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Ultraviolet radiation is at shorter wavelengths than the visible spectrum (400 to 700 nm) and is divided into three components: UV-A (315 to 400 nm), UV-B (280 to 315 nm) and UV-C (less than 280 nm). The shorter wavelengths that comprise UV-B are the most dangerous portion of UV radiation that can reach ground level. Atmospheric ozone shields life at the surface from most of the UV-B and almost all of the UV-C. UV-A and UV-B are reduced by a small amount from Rayleigh scattering in the atmosphere. All forms of UV radiation are reduced by cloud cover. Persistent lack of cloud cover in some regions (e.g. Australia and South Africa) increases the danger from UV radiation compared to similar latitudes in the Northern Hemisphere. Chemical processes in the atmosphere can affect the amount of ozone, and therefore, the level of protection provided by the ozone in the stratosphere and troposphere. This thinning of the atmospheric ozone leads to elevated levels of UV-B at the earth's surface and increases the risks of DNA damage and other cellular damage in living organisms.

Tropospheric Ozone Data

Tropospheric column ozone (TCO) and stratospheric column ozone (SCO), gridded data products are made available from NASA Goddard Space Flight Center, Code 916 via either direct ftp, the Web, or electronic mail. Monthly averaged TCO and SCO data are derived in the tropics for January 1979 to the present using the Convective Cloud Differential (CCD) method. The CCD method is a special case of the generalized Cloud Slicing algorithm. Since 1998 and to the end of year 2003, the Cloud Slicing data have been used in at least 16 refereed publications. Five papers on tropospheric ozone were published in 2003 by Code 916 members. The Cloud Slicing data, algorithm description, and data documentation may be obtained at http://hyperion.gsfc.nasa.gov/Data_services/Data.html. For more information, contact Jerry Ziemke (Jerald.R.Ziemke.1@gsfc.nasa.gov).

4.4 Data Analysis

A considerable effort by our scientists is spent in analyzing the data from a vast array of instruments and field campaigns. This section details some of the major activities in this endeavor.

Atmospheric Ozone Research

The Clean Air Act Amendment of 1977 assigned NASA the major responsibility for studying the ozone layer.

Data from many ground-based, aircraft, and satellite missions are combined with meteorological data to understand the factors that influence the production and loss of atmospheric ozone. Analysis is conducted over different temporal and spatial scales, ranging from studies of transient filamentary structures that play a key role in mixing the chemical constituents of the atmosphere to investigations of global-scale features that evolve over decades.

The principal goal of these studies is to understand the complex coupling between natural phenomena, such as volcanic eruptions and atmospheric motions, with human-made pollutants, such as those generated by agricultural and industrial activities. These nonlinear couplings have been shown to be responsible for the development of the well-known Antarctic ozone hole.

An emerging area of research is to understand the transport of chemically active trace gases across the tropopause boundary, both into the stratosphere from the troposphere, and out of the stratosphere to the troposphere. It has been suggested that changes in atmospheric circulation caused by greenhouse warming may affect this transport and, thus, delay the anticipated recovery of the ozone layer in response to phase-out of CFCs. For more information, contact Paul A. Newman (Paul.A.Newman@nasa.gov).

Dust Aerosol and Radiative Forcing

The aerosol data is also being used to assess the degree of radiative forcing (excess heating) in the atmosphere caused by the presence of dust. The results are used to estimate heating rates related to climate change. The dust aerosol sources and satellite derived winds have been incorporated in the Global Ozone Chemistry Aerosol Radiation Transport (GOCART) model to map out trajectory plumes for any time of the day, and to give altitude distributions. One of the applications of the GOCART model to aerosol data is the estimation of air quality in the boundary layer. This is especially important in Africa where the intense boundary layer dust storms are implicated in the incidence of meningitis with epidemic proportions. The results are of intense interest to the Centers for Disease Control and Prevention and the World Health Organization (WHO). For more information, contact Jay Herman (Jay.R.Herman@nasa.gov).

Observing System Simulation Experiments

Observing system simulation experiments (OSSEs) are an important tool for designing spaceborne meteorological sensors, developing optimum methods for using satellite soundings and winds, and assessing the influence of satellite data on weather prediction and climate research. At the present time, OSSEs are being conducted to (1) provide a quantitative assessment of the potential impact of currently proposed space-based observing systems on global change research, (2) evaluate new methodology for assimilating specific observing systems, and (3) evaluate tradeoffs in the design and configuration of these observing systems. Specific emphasis over the past year has been on space-based lidar winds and other advanced passive sensors. For more information, contact Robert Atlas (Robert.M.Atlas@nasa.gov).

Atmospheric Hydrologic Processes and Climate

One of the main thrusts in climate research in the Laboratory is to identify natural variability on seasonal, interannual, and interdecadal time scales, and to isolate the natural variability from the human-made global-change signal. Climate diagnostic studies use a combination of remote-sensing data, historical climate data, model output, and assimilated data. Diagnostic studies are combined with modeling studies to unravel physical processes underpinning climate variability and predictability. The key areas of research include ENSO, monsoon variability, intraseasonal oscillation, air - sea interaction, and water vapor and cloud feedback processes. More recently, the possible impact of anthropogenic aerosol on regional and global atmospheric water cycle is also included. A full array of standard and advanced analytical techniques, including wavelets transform, multivariate empirical orthogonal functions, singular value decomposition, canonical correlation analysis, and nonlinear system analysis are used.

Maximizing the use of satellite data for better interpretation, modeling, and eventually prediction of geophysical and hydroclimate systems is a top priority of research in the Laboratory. Satellite-derived data sets for key hydroclimate variables such as rainfall, water vapor, clouds, surface wind, sea surface temperature, sea level heights, and land surface characteristics are obtained from a number of different projects: the EOS Terra and Aqua series; TRMM, Quick Scatterometer Satellite (QuikSCAT) and Topography Experiment (TOPEX)/Poseidon; the Earth Radiation Budget Experiment (ERBE); Clouds and the Earth's Radiant Energy System (CERES); the International Satellite Cloud Climatology Project (ISCCP); Advanced Very High Resolution Radiometer (AVHRR); TOMS; SSM/I; MSU; and TOVS Pathfinder. Data will be used extensively for diagnostic and modeling studies. For more information, contact William Lau (William.K.Lau@nasa.gov).

Rain Estimation Techniques from Satellites

Rainfall information is a key element in studying the hydrologic cycle. A number of techniques have been developed to extract rainfall information from current and future spaceborne sensor data, including the TRMM satellite and the Advanced Microwave Scanning Radiometer (AMSR) on EOS Aqua.

The retrieval techniques include the following:

(1) A physical, multifrequency technique that relates the complete set of microwave brightness temperatures to rainfall rate at the surface. This multifrequency technique also provides information on the vertical structure of hydrometeors and on latent heating through the use of a cloud ensemble model. The approach has recently been extended to combine spaceborne radar data with passive microwave observations for improved estimations.

(2) An empirical relationship that relates cloud thickness, humidity, and other parameters to rain rates, using TOVS and Aqua - AIRS sounding retrievals.

(3) An analysis technique that uses TRMM, other low-orbit microwave, geosynchronous, infrared, and rain gauge information to provide a merged, global precipitation analysis. The merged analysis technique is now being used to produce global daily and quasi-global (50°N,50°S) 3-hour analyses.

The satellite-based rainfall information has been used to study the global distribution of atmospheric latent heating, the impact of ENSO on global-scale and regional precipitation patterns, the climatological contribution of tropical cyclone rainfall, and the validation of global models. For more information, contact Robert Adler (Robert.F.Adler@nasa.gov).

Rain Measurement Validation for the TRMM

The objective of the TRMM Ground Validation Program (GVP) is to provide reliable, instantaneous area- and time-averaged rainfall data from several representative tropical and subtropical sites worldwide for comparison with TRMM satellite measurements. Rainfall measurements are made at Ground Validation (GV) sites equipped with weather radar, rain gauges, and disdrometers. A range of data products derived from measurements obtained at GV sites is available via the Goddard DAAC. With these products, the validity of TRMM measurements is being established with accuracies that meet mission requirements. For more information, contact Robert Adler (Robert.F.Adler@nasa.gov).

Unified Onboard Processing and Spectrometry

Increasingly, scientists agree that spectrometers are the wave of the future in passive Earth remote sensing. The difficulty, however, stems from the vast volume of data generated by an imaging spectrometer sampling in the spatial and spectral dimensions. The data volume from an advanced spectrometer could easily require 10 times the present EOS Data Information System (EOSDIS) capacity—something NASA simply cannot afford. A group of scientists and engineers at GSFC, led by Si-Chee Tsay, is funded (2nd year) by ESTO Advanced Component Technologies (ACT), which is a project to unify onboard processing techniques with compact, low-power, low-cost, Earth-viewing spectrometers being developed for eventual space missions. The philosophy is that spectrometry and its onboard processing algorithms must advance in lockstep, and eventually unite in an indistinguishable fashion. We envision a future in which archives of the spectrometer output will not be a monstrous data dump of spectra, but rather the information content of those spectra, undoubtedly a much smaller and more valuable data stream. In the meantime, we must quickly find ways to losslessly compress (onboard) spectra, using a combination of physics-based removal and proximal differencing, to the maximum extent possible. We are also exploring lossy compressions for specific applications in Earth sciences. For further information, contact Si-Chee Tsay (si-chee.tsay-1@nasa.gov).

4.5 Modeling

Modeling is an important aspect of our research, and is the path to understanding the physics and chemistry of our environment. Models are intimately connected with the data measured by our instruments: models are used to interpret data, and the data is combined with models in data assimilation. Our modeling activities are highlighted below.

Aerosol Modeling (GOCART)

Aerosol radiative forcing is one of the largest uncertainties in assessing global climate change. To understand the various processes that control aerosol properties and to understand the role of aerosol in atmospheric chemistry and climate, we have developed an atmospheric aerosol model, the GOCART model. This model uses the meteorological fields produced by the Goddard Global Modeling and Assimilation Office (GMAO, Code 900.3), and includes major types of aerosols: sulfate, dust, black carbon, organic carbon, and sea salt. Among these, sulfate, and black- and organic carbon originate mainly from human activities, such as fossil fuel combustion and biomass burning; while dust and sea salt are mainly generated by natural processes, for example, uplifting dust from deserts by strong winds.

We have been using the GOCART model to study intercontinental transport, global air quality, aerosol radiative forcing, and aerosol-chemistry-climate interactions. It has also been used to support aircraft and satellite observations, including involvement in the Aerosol Characterization Experiment (ACE)-Asia field experiment, analyzing satellite data from TOMS and MODIS and from the AERONET sun photometer network. The output of the model is used by many groups worldwide for studies of air pollution, radiation budget, tropospheric chemistry, hydrological cycles, and climate change. For more information, contact Mian Chin (Mian.Chin@nasa.gov), or go to the Web site http://code916.gsfc.nasa.gov/People/Chin/aot.html.

Cloud and Mesoscale Modeling

The mesoscale model 5 (MM5) and cloud-resolving (Goddard Cumulus Ensemble - [GCE]) models are used in a wide range of studies, including investigations of the dynamic and thermodynamic processes associated with cyclones, hurricanes, winter storms, cold rainbands, tropical and mid-latitude deep convective systems, surface (i.e., ocean and land, and vegetation and soil) effects on atmospheric convection, cloud - chemistry interactions, cloud - aerosol interactions, and stratospheric - tropospheric interaction. Other important applications include long-term integrations of the models that allow for the study of air - sea, cloud - aerosol, cloud - chemistry (transport) and cloud - radiation interactions and their role in cloud - climate feedback mechanisms. Such simulations provide an integrated system-wide assessment of important factors such as surface energy, precipitation efficiency and radiative exchange processes, and diabatic heating and water budgets associated with tropical, subtropical, and mid-latitude weather systems. Data collected during several major field programs, GATE1, (1974), PRESTORM (1985), TOGA COARE (1992 - 1993), ARM (1997, 2000), SCSMEX (1998), TRMM LBA (1999), TRMM KWAJEX (1999), WMO01 (2001), and CAMEX4 (2001) has been used to improve, as well as to validate, the GCE and MM5 model. The MM5 was also improved in order to study regional climate variation, hurricanes, and severe weather events (i.e., flash floods in central U.S. and China). The models also are used to develop retrieval algorithms. For example, GCE model simulations are being used to provide TRMM investigators with four-dimensional cloud data sets to develop and improve TRMM rainfall and latent heating retrieval algorithms, and moist processes represented in large scale models (i.e., weather forecast model and climate model). Both Open MultiProcessing (OpenMP) and Message Passing Interface (MPI) versions of the GCE model are developed and can be efficiently run on different computing platforms. This allows the GCE model to be used in many applications related to NASA missions.

The scientific output of the modeling activities was again exceptional in 2003 with 14 new papers published and many more submitted. For more information, contact Wei-Kuo Tao (WeiKuo.Tao.1@gsfc.nasa.gov).

1The definitions for the acronyms that follow can be found in Sect. 8.

Physical Parameterization in Atmospheric GCM

The development of submodels of physical processes (physical parameterizations) is an integral part of climate modeling activity. Laboratory scientists are actively involved in developing and improving physical parameterizations of the major radiative transfer moist processes, clouds and cloud radiation interaction, and Earth - atmosphere interaction processes. The accuracy of cloud process-interactions is extremely important for eliminating climate-model biases; this is vital to a better understanding of the global water and energy cycles.

For atmospheric radiation, we are developing efficient, accurate, and modular longwave and shortwave radiation codes. The radiation codes allow efficient computation of climate sensitivities to water vapor, cloud microphysics, and optical properties. The codes also allow us to compute the global warming potentials of carbon dioxide and various trace gases.

For atmospheric hydrologic processes, we are evaluating and eliminating the simulation biases of our Goddard-developed prognostic cloud-scale dynamics and cloud water substance scheme that includes representation of source and sink terms, as well as horizontal and vertical advection of cloud water substance. This scheme incorporates attributes from physically based cloud life cycles, including the effects of convective updrafts and downdrafts, cloud microphysics within convective towers and anvils, cloud - radiation interactions, and cloud inhomogeneity corrections. The boundary-layer clouds are consistently derived from and linked to boundary-layer convection. We are evaluating coupled radiation and the prognostic water schemes with in situ observations from the ARM Cloud and Radiation Test Bed (ARM CART) and TOGA COARE IOPs, as well as satellite data. For land - surface processes, a new snow physics package has been developed and evaluated with GEWEX GSWP data sets. It is currently in the Goddard EOS (GEOS) National Center for Atmospheric Research (NCAR) finite volume General Circulation Model (GCM). Moreover, the soil moisture prediction is extended down to 5 m, which often goes through the groundwater table. All these improvements have been found to better represent the hydrologic cycle in a climate simulation. Currently, we are performing objective intercomparisons of different parameterization concepts (applied to models and satellite data retrievals) within the GSFC Laboratories. NCAR and GISS scientists are our active collaborators. For more information, contact Yogesh Sud (Yogesh.C.Sud@nasa.gov).

Trace Gas Modeling

The Atmospheric Chemistry and Dynamics Branch has developed two- and three-dimensional (2-D and 3-D, respectively) models to understand the behavior of ozone and other atmospheric constituents. We use the 2-D models primarily to understand global scale features that evolve in response to both natural effects, such as variations in solar luminosity in ultraviolet, volcanic emissions, or solar proton events, and human effects, such as changes in chlorofluorocarbons (CFCs), nitrogen oxides, and hydrocarbons. Three-dimensional stratospheric chemistry and transport models simulate the evolution of ozone and trace gases that affect ozone. The constituent transport is calculated using meteorological fields (winds and temperatures) generated by the GMAO or using meteorological fields that are output from a GCM. These calculations are appropriate to simulate variations in ozone and other constituents for time scales ranging from several days or weeks to seasonal, annual, and multiannual. The model simulations are compared with observations, with the goal of illuminating the complex chemical and dynamical processes that control the ozone layer, thereby improving our predictive capability.

The modeling effort has evolved in four directions:

(1) Lagrangian models are used to calculate the chemical evolution of an air parcel along a trajectory. The Lagrangian modeling effort is primarily used to interpret aircraft and satellite chemical observations.

(2) Two-dimensional noninteractive models have comprehensive chemistry routines, but use specified, parameterized dynamics. They are used in both data analysis and multidecadal chemical assessment studies.

(3) Two-dimensional interactive models include interactions among photochemical, radiative, and dynamical processes, and are used to study the dynamical and radiative impact of major chemical changes.

(4) Three-dimensional CTMs have a complete representation of photochemical processes and use input meteorological fields from either the data assimilation system or from a general circulation model for transport. The constituent fields calculated using winds from a new GCM developed jointly by the GMAO and NCAR exhibit many observed features. We are coupling this GCM with the stratospheric photochemistry from the CTM with the goal of developing a fully interactive 3-D model that is appropriate for assessment calculations. We are also using output from this GCM in the current CTM for multidecadal simulations. The CTM is being improved by implementation of a chemical mechanism suitable for both the upper troposphere and lower stratosphere. This capability is needed for interpretation of data from EOS Aura, to be launched in June 2004.

The Branch uses trace gas data from sensors on the Upper Atmosphere Research Satellite (UARS), on other satellites, from ground-based platforms, from balloons, and from various NASA-sponsored aircraft campaigns to test model processes. The integrated effects of processes such as stratosphere troposphere exchange, not resolved in 2-D or 3-D models, are critical to the reliability of these models. For more information, contact Anne Douglass (Anne.R.Dougass@nasa.gov).

4.6 Support for NOAA Operational Satellites

In the preceding pages, we examined the Laboratory for Atmosphere's Research and Development work in measurements, data sets, data analysis, and modeling. In addition, Goddard supports NOAA's operational remote sensing requirements. Laboratory project scientists support the NOAA Polar Orbiting Environmental Satellite (POES) and the Geostationary Operational Environmental Satellite (GOES) Project Offices. Project scientists ensure scientific integrity throughout mission definition, design, development, operations, and data analysis phases for each series of NOAA platforms. Laboratory scientists also support the NOAA SBUV/2 ozone measurement program. This program is now operational within the NOAA/National Environmental Satellite Data and Information Service (NESDIS). A series of SBUV/2 instruments fly on POES. Postdoctoral scientists work with the project scientists to support development of new and improved instrumentation and to perform research using NOAA's operational data.

Laboratory members are actively involved in the NPOESS Internal Government Studies (IGS) and support the Integrated Program Office (IPO) Joint Agency Requirements Group (JARG) activities. Likewise, the Laboratory is supporting the formulation phase for the next generation GOES mission, known as GOES-R, which will supply a hundredfold increase in real-time data. One Laboratory scientist is involved in specifying the requirements for the advanced GOES-R atmospheric sounder, called the High Resolution Environmental Suite (HES), writing the Request for Proposal (RFP) for HES, and serving on the HES Source Evaluation Board. For more information, contact Dennis Chesters (Dennis.Chesters@nasa.gov).

GOES

GSFC project engineering and scientific personnel support NOAA for GOES. GOES supplies images and soundings to monitor atmospheric processes in real time, such as moisture, winds, clouds, and surface conditions. GOES observations are used by climate analysts to study the diurnal variability of clouds and rainfall, and to track the movement of water vapor in the upper troposphere. The GOES satellites also carry an infrared multichannel radiometer, which NOAA uses to make hourly soundings of atmospheric temperature and moisture profiles over the United States to improve numerical forecasts of local weather. The GOES project scientist at Goddard provides free public access to real-time weather images via the World Wide Web (http://goes.gsfc.nasa.gov/). For more information, contact Dennis Chesters (Dennis.Chesters@nasa.gov).

NPOESS

The first step in instrument selection for NPOESS was completed with Laboratory personnel participating on the Source Evaluation Board as technical advisors. Laboratory personnel were involved in evaluating proposals for the Ozone Mapper and Profiler System (OMPS) and the Crosstrack Infrared Sounder (CrIS), which will accompany the Advanced Technology Microwave Sounder (ATMS), an Advanced Microwave Sounding Unit (AMSU)-like crosstrack microwave sounder. Collaboration with the IPO continues through the Sounder Operational Algorithm Team (SOAT) and the Ozone Operational Algorithm Team (OOAT), which will provide advice on operational algorithms and technical support on various aspects of the NPOESS instruments. In addition to providing an advisory role, members of the Laboratory are conducting internal studies to test potential technology and techniques for NPOESS instruments. We have conducted numerous trade studies involving CrIS and ATMS, the advanced infrared and microwave sounders, which will fly on NPP and NPOESS. Simulation studies were conducted to assess the ability of AIRS to determine atmospheric CO2, CO, and CH4. These studies indicate that total CO2 can be obtained to 2 ppm (0.5%) from AIRS under clear conditions, total CH4 to 1%, and total CO to 15%. This shows that AIRS should be able to produce useful information about atmospheric carbon. For more information, contact Joel Susskind (Joel.Susskind-1@nasa.gov).

CrIS for NPP

CrIS is a high-spectral - resolution interferometer infrared sounder with capabilities similar to those of AIRS. AIRS was launched with AMSU-A and the Humidity Sounder for Brazil (HSB) on the EOS Aqua platform on March 5, 2002. Scientific personnel have been involved in developing the AIRS Science Team algorithm to analyze the AIRS/AMSU/HSB data. Current results with AIRS/AMSU/HSB data demonstrate that the temperature sounding goals for AIRS, i.e., root mean squared (RMS) accuracy of 1K in 1 km layers of the troposphere under partial cloud cover, are being met over the ocean. The AIRS soundings will be used in a pseudo-operational mode by NOAA/NESDIS and the NOAA/National Center for Environmental Prediction (NCEP). Simulation studies were conducted for the IPO to compare the expected performance of AIRS/AMSU/HSB with that of CrIS, as a function of instrument noise, together with AMSU/HSB. The simulations will help in assessing the noise requirements for CrIS to meet the NASA sounding requirements for the NPP bridge mission in 2006. Trade studies have also been done for ATMS, which will accompany CrIS on the NPP mission and replace AMSU/HSB. For more information, contact Joel Susskind (Joel.Susskind-1@nasa.gov).

Ozone Mapper Profiler Suite (OMPS)

OMPS will become the next U.S. operational ozone sounder to fly on NPOESS. The instrument suite has heritage from TOMS and SBUV for total ozone mapping and ozone profiling. The need for high performance profiles providing better vertical resolution in the lower stratosphere resulted in the addition of a limb scattering profiler to the suite. The limb scattering profiler instrument has heritage from the two SOLSE/LORE shuttle demonstration flights in 1997 and 2002. These missions were developed by our Laboratory with partial support by the IPO. The second flight was conducted on the Space Shuttle Columbia in 2003 and much data was lost in that tragedy. Recovered near-real time data are being analyzed and their results are being used to aid development of the OMPS operational limb scattering algorithm.

Laboratory scientists continue to support the IPO through the OOAT and through a NASA Research Announcement (NRA) selection for the NPP Science Team. Laboratory scientists are conducting algorithm research, advising on pre- and postlaunch calibration procedures, and making recommendations for validation. They participate in reviews for the OMPS instrument contractor and the NPOESS system integrator. An algorithm has been developed to analyze the Stratospheric Aerosol and Gas Experiment (SAGE) III data when SAGE III operates in a limb scattering mode, which will simulate retrievals expected from the OMPS profiler. This work is an extension of the retrievals used for the SOLSE-1 and SOLSE-2 missions. The advanced ultraviolet and visible radiative transfer models developed in the Laboratory over the last two decades enable this research. The two decades of experience in TOMS and SBUV calibration and validation will also be applied to OMPS. For more information, contact Ernest Hilsenrath (Ernest.Hilsenrath@nasa.gov) and Richard McPeters (Richard.D.McPeters@nasa.gov).

Holographic Scanning Lidar Telescope Technology

The Integrated Program Office supports the development of Holographic Scanning Lidar Telescope technology as a risk reduction for lidar applications on NPOESS, including direct detection wind lidar systems. Currently used in ground-based and airborne lidar systems, holographic scanning telescopes operating in the visible and near infrared wavelength region have reduced the size and weight of scanning receivers by a factor of three. We are currently investigating extending the wavelength region to the ultraviolet, increasing aperture sizes to 1 m and larger, and eliminating all mechanical moving components by optically addressing multiplexed holograms in order to perform scanning. This last development should reduce the weight of large aperture scanning receivers by another factor of three. For more information on the Holographic Optical Telescope and Scanner (HOTS) technology, visit the Web site at http://harlie.gsfc.nasa.gov/ or contact Geary Schwemmer (Geary.K.Schwemmer@nasa.gov).

Tropospheric Wind Profile Measurements

Global tropospheric wind profile measurements are important for understanding atmospheric dynamics on a variety of time scales. Numerous studies have shown that direct measurement of winds will greatly improve numerical weather prediction. Because of this importance, the civilian and Department of Defense (DoD) operational weather forecasting communities have identified tropospheric winds as the number one unaccommodated measurement in the Integrated Operational Requirements Document (IORD-1) for NPOESS, the next generation polar orbiting weather satellite. The Laboratory is using these requirements to develop new technologies and Direct Detection Doppler Lidar measurement techniques to measure tropospheric wind profiles from ground, air, and spaceborne platforms. The NPOESS Integrated Program Office is supporting the effort. For more information, contact Bruce Gentry (Bruce.M.Gentry@nasa.gov).

4.7 Project Scientists

Spaceflight missions at NASA depend on cooperation between two upper-level managers, the project scientist and the project manager, who are the principal leaders of the project. The project scientist provides continuous scientific guidance to the project manager while simultaneously leading a science team and acting as the interface between the project and the scientific community at large. Table 4 lists project and deputy project scientists for current missions; Table 5 lists the validation and mission scientists for various campaigns.

Table 4: Laboratory for Atmospheres project and deputy project scientists.

PROJECT SCIENTISTS

DEPUTY PROJECT SCIENTISTS

Name

Project

Name

Project

Robert Adler

TRMM

Anne Douglass

EOS Aura, UARS

Pawan K. Bhartia

TOMS

Ernest Hilsenrath

EOS Aura

Robert Cahalan

EOS SORCE

Hans Mayr

AIM

Dennis Chesters

GOES

Marshall Shepherd

GPM

Jay Herman

DSCOVR

Si-Chee Tsay

EOS Terra

Charles Jackman

UARS

   

Eric Smith

GPM

   

Joel Susskind

POES

   

Table 5: Laboratory for Atmospheres Campaigns and Mission Scientists

EOS VALIDATION SCIENTIST

FIELD/AIRCRAFT CAMPAIGN & MISSION SCIENTISTS

Name

Mission

Name

Campaign

David Starr

EOS

Robert Atlas

GTWS

   

Robert Cahalan

THOR Validation

   

Belay Demoz

IHOP

   

Bruce Gentry

HARGLO-2

   

Thomas McGee

New Zeeland Intercomparison

   

Matt McGill

Cloud Sat, CALIPSO

   

Paul Newman

SOLVE II

   

Geary Schwemmer

HARGLO-2

   

David Starr

CRYSTAL/FACE

   

Si-Chee Tsay

ACE Asia II

   

Judd Welton

MPL/Net

 

4.8 Interactions with Other Scientific Groups

Interactions with the Academic Community

The Laboratory relies on collaboration with university scientists to achieve its goals. Such relationships make optimum use of government facilities and capabilities and those of academic institutions. These relationships also promote the education of new generations of scientists and engineers. Educational programs include summer programs for faculty and students, fellowships for graduate research, and associateships for postdoctoral studies. A number of Laboratory members teach courses at nearby universities and give lectures and seminars at U.S. and foreign universities. (See Sect. 6 for more details on the education and outreach activities of our Laboratory). The Laboratory frequently supports workshops on a wide range of scientific topics of interest to the academic community, as shown in Appendix B5 located on the Laboratory's Web site http://atmospheres.gsfc.nasa.gov.

NASA and non-NASA scientists work together on NASA missions, experiments, and instrument and system development. Similarly, several Laboratory scientists work on programs residing at universities or other federal agencies.

The Laboratory routinely makes its facilities, large data sets, and software available to the outside community. The list of refereed publications, presented in Appendix B7 located on the Laboratory's Web site http://atmospheres.gsfc.nasa.gov, reflects our many scientific interactions with the outside community; over 85% of the publications involve coauthors from institutions outside the Laboratory.

A prime example of the collaboration between the academic community and the Laboratory is given in this list of collaborative relationships via memoranda of understanding or cooperative agreements:

 

A more complete Directorate list of such collaborations is given at the Web site http://earthsciences.gsfc.nasa.gov/metadot/index.pl/collab.html.

These collaborative relationships have been organized to increase scientific interactions between the Earth Sciences Directorate at GSFC and the faculty and students at the participating universities. One means of increasing these interactions is a new initiative the Earth Sciences Directorate has established, which will increase our sponsorship of graduate students. The Laboratory for Atmospheres is participating in this program, which will partner Laboratory scientists with graduate students. Our scientists will advise the student, serve on the thesis committee, visit the university, host the student at GSFC, and collaborate with the student's thesis advisor.

In addition, university and other outside scientists visit the Laboratory for periods ranging from one day to as long as two years. (See Appendices B1 and B4 for lists of recent visitors and seminars, respectively, on the Laboratory's Web site.) Some of these appointments are supported by Resident Research Associateships offered by the National Research Council (NRC) of the National Academy of Sciences; others, by the Visiting Scientists and Visiting Fellows Programs currently managed by the GEST Center. Visiting Scientists are appointed for up to two years and carry out research in pre-established areas. Visiting Fellows are appointed for up to one year and are free to carry out research projects of their own design. (See Appendix B3 on the Laboratory's Web site for a list of NRC Research Associates, GEST Center Visiting Scientists, Visiting Fellows, and Associates of the Joint Institutes during 2003.)

Interactions with Other NASA Centers and Federal Laboratories

The Laboratory maintains strong, productive interactions with other NASA Centers and Federal laboratories.

Our ties with the other NASA Centers broaden our knowledge base. They allow us to complement each other's strengths, thus increasing our competitiveness while minimizing duplication of effort. They also increase our ability to reach the Agency's scientific objectives.

Our interactions with other Federal laboratories enhance the value of research funded by NASA. These interactions are particularly strong in ozone and radiation research, data assimilation studies, water vapor and aerosol measurements, ground-truth activities for satellite missions, and operational satellites. An example of interagency interaction is the NASA/NOAA/National Science Foundation (NSF) Joint Center for Satellite Data Assimilation (JCSDA), which is building on prior collaborations between NASA and NCEP to exploit the assimilation of satellite data for both operational and research purposes.

Interactions with Foreign Agencies

The Laboratory has cooperated in several ongoing programs with non-U.S. space agencies. These programs involve many of the Laboratory scientists.

Major efforts include TRMM, with the Japanese National Space Development Agency (NASDA); the Huygens Probe GCMS, with the ESA (Centre Nationale d'Etudes Spatiales [CNES]); the TOMS Program, with NASDA and the Russian Scientific Research Institute of Electromechanics (NIIEM); the Neutral Mass Spectrometer (NMS) instrument, with the Japanese Institute of Space and Aeronautical Science (ISAS); and climate research with various institutes in Europe, South America, Africa, and Asia. Another example of international collaboration was in the SOLVE II (SAGE III Ozone Loss and Validation Experiment) campaign, which was conducted in close collaboration with the Validation of International Satellites and study of Ozone Loss (VINTERSOL) campaign sponsored by the European Commission. More than 350 scientists from the United States, the European Union, Canada, Iceland, Japan, Norway, Poland, Russia, and Switzerland participated in this joint effort which took place in January 2003.

Laboratory scientists interact with about 20 foreign agencies, about an equal number of foreign universities, and several foreign companies. The collaborations vary from extended visits for joint missions, to brief visits for giving seminars, or working on joint science papers.

4.9 Commercialization and Technology Transfer

The Laboratory for Atmospheres fully supports Government - Industry partnerships, SBIR projects, and technology transfer activities. Successful technology transfer has occurred on a number of programs in the past and new opportunities will become available in the future. Past examples include the MPL and holographic optical scanner technology. Industry now uses these innovations for topographic mapping, medical imaging, and for multiplexing in telecommunications. New research proposals involving technology development will have strong commercial partnerships wherever possible.